| // Copyright 2015 The LUCI Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package clock |
| |
| import ( |
| "context" |
| "time" |
| ) |
| |
| // Unique value for clock key. |
| var clockKey = "clock.Clock" |
| |
| // Factory is a generator function that produces a Clock instnace. |
| type Factory func(context.Context) Clock |
| |
| // SetFactory creates a new Context using the supplied Clock factory. |
| func SetFactory(ctx context.Context, f Factory) context.Context { |
| return context.WithValue(ctx, &clockKey, f) |
| } |
| |
| // Set creates a new Context using the supplied Clock. |
| func Set(ctx context.Context, c Clock) context.Context { |
| return SetFactory(ctx, func(context.Context) Clock { return c }) |
| } |
| |
| // Get returns the Clock set in the supplied Context, defaulting to |
| // SystemClock() if none is set. |
| func Get(ctx context.Context) (clock Clock) { |
| if v := ctx.Value(&clockKey); v != nil { |
| if f, ok := v.(Factory); ok { |
| clock = f(ctx) |
| } |
| } |
| if clock == nil { |
| clock = GetSystemClock() |
| } |
| return |
| } |
| |
| // Now calls Clock.Now on the Clock instance stored in the supplied Context. |
| func Now(ctx context.Context) time.Time { |
| return Get(ctx).Now() |
| } |
| |
| // Sleep calls Clock.Sleep on the Clock instance stored in the supplied Context. |
| func Sleep(ctx context.Context, d time.Duration) TimerResult { |
| return Get(ctx).Sleep(ctx, d) |
| } |
| |
| // NewTimer calls Clock.NewTimer on the Clock instance stored in the supplied |
| // Context. |
| func NewTimer(ctx context.Context) Timer { |
| return Get(ctx).NewTimer(ctx) |
| } |
| |
| // After waits a duration using the Clock instance stored in the supplied |
| // Context. Then sends the current time over the returned channel. |
| // |
| // If the supplied Context is canceled, the timer will expire immediately. |
| func After(ctx context.Context, d time.Duration) <-chan TimerResult { |
| return after(ctx, Get(ctx), d) |
| } |
| |
| func after(ctx context.Context, c Clock, d time.Duration) <-chan TimerResult { |
| t := c.NewTimer(ctx) |
| t.Reset(d) |
| return t.GetC() |
| } |
| |
| // Since is an equivalent of time.Since. |
| func Since(ctx context.Context, t time.Time) time.Duration { |
| return Now(ctx).Sub(t) |
| } |
| |
| // Until is an equivalent of time.Until. |
| func Until(ctx context.Context, t time.Time) time.Duration { |
| return t.Sub(Now(ctx)) |
| } |